Vitamin D, refers to a group of substances found in many living things. Especially vitamin D2 and vitamin D3 are important for humans. and The peculiarity of all variants of vitamin D is similar to cholesterol. In human metabolism, vitamin D is transformed in many ways.
Mode of action of vitamin D
Vitamin D is produced in sufficient quantities by the healthy body through the action of sunlight. The precursors from which vitamin D is formed are present in food in sufficient quantities.
The goal of these processes is always the production of hormones. These processes are not yet fully known in detail. Well described is the function of vitamin D in the form of calcitriol. This hormone is important for the calcium balance and the growth and maintenance of healthy bones.
In addition, vitamin D acts as calcitriol on several other organs. For example, the hormone plays an important role in the regulatory circuits of the immune system. Calcitriol is also involved in the control of skin, muscle and nerve functions.
All hormones from the vitamin D family have similarly broad effects. The body can produce vitamin D in the skin itself. However, sufficient exposure to sunlight is required for this.
Importance
The most important significance of vitamin D is known by the most common deficiency symptoms of vitamin D in the past. Children who had too little exposure to sunlight developed rickets. The disease is associated with severe malformations of the bones. Only treatment with cod liver oil was able to prevent further growth damage. Fish oil is rich in vitamin D.
Today, physicians associate many diseases with a deficiency of vitamin D. The majority of these diseases, however, are caused by a lack of vitamin D. However, this is largely conjecture, which is admittedly supported by scientific studies. Infectious diseases occur more frequently when there is an undersupply of vitamin D. This underlines the functional importance of vitamin D for the immune system.
An insufficient supply of vitamin D is also suspected of promoting some types of cancer. The importance of vitamin D for the metabolism is shown by the increase in dangerous blood lipid levels, which is partly attributed to too little vitamin D. Vitamin D is thought to reduce the risk of some diseases of the nervous system.
This is suspected for multiple sclerosis and dementia.
An adequate supply of vitamin D is crucial for general performance. Intensive physical activity such as sports or heavy labor are therefore also determined by the amount of vitamin D available.
Elderly people and small children have a significantly increased need for vitamin D. It must be taken into account that vitamin D can also have a slightly toxic effect in the case of extreme overdosage. The symptoms are similar to a migraine, in addition, cardiac arrhythmias can occur.
Occurrence in food
Vitamin D is produced in sufficient quantities by the healthy body through the action of sunlight. The precursors from which vitamin D is formed are present in food in sufficient quantities.
Under normal conditions, therefore, the body does not require a supply of vitamin D. However, if certain conditions are present, the formation of vitamin D may be impaired. This probably occurs when a genetic predisposition inhibits the natural process of vitamin D formation. There are also life circumstances that lead to reduced absorption of solar radiation.
Examples of this are long periods of illness or advanced age. In all these cases, a supplementary supply of vitamin D can be useful. Vitamin D is found in larger quantities almost exclusively in animal foods such as fish oil (cod liver oil) and fatty fish, beef liver, eggs and milk. Avocados are good plant sources of vitamin D.
